Mesprit is one of the lake guardians of Sinnoh who appeared to Dia when he was young. Team Galactic awakened it at Lake Verity and captured it to harvest its crystals for creation of the Red Chain. It was later set free from Dia, Pearl and Platinum in exchange for their Pokedexes. It joined the legendary battle in the Distortion World after helping the Senior Team Galactic Grunt return the Pokedexes to the Sinnoh Dex Holders.